Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
3,959
result(s) for
"Birds. Color."
Sort by:
National Geographic bird coloration
Seventeen short chapters with engaging narrative and lots of photos with information-packed captions illustrate the mechanisms by which birds produce the characteristic and sometimes brilliant coloration of their feathers and other body parts.
Book
AVIAN VISION AND THE EVOLUTION OF EGG COLOR MIMICRY IN THE COMMON CUCKOO
Coevolutionary arms races are a potent force in evolution, and brood parasite-host dynamics provide classical examples. Different host-races of the common cuckoo, Cuculus canorus, lay eggs in the nests of other species, leaving all parental care to hosts. Cuckoo eggs often (but not always) appear to match remarkably the color and pattern of host eggs, thus reducing detection by hosts. However, most studies of egg mimicry focus on human assessments or reflectance spectra, which fail to account for avian vision. Here, we use discrimination and tetrachromatic color space modeling of bird vision to quantify egg background and spot color mimicry in the common cuckoo and 11 of its principal hosts, and we relate this to egg rejection by different hosts. Egg background color and luminance are strongly mimicked by most cuckoo host-races, and mimicry is better when hosts show strong rejection. We introduce a novel measure of color mimicry—\" color overlap\"—and show that cuckoo and host background colors increasingly overlap in avian color space as hosts exhibit stronger rejection. Finally, cuckoos with better background color mimicry also have better pattern mimicry. Our findings reveal new information about egg mimicry that would be impossible to derive by the human eye.
Journal Article
Baby's first book of birds & colors
\"From the eastern bluebird and blue jay to the scarlet tanager and northern cardinal, little ones will discover the natural world and learn the names and colors of Phyllis Limbacher Tildes's exquisitely illustrated birds in their natural habitats.
Book
Evaluation of a Reproductive Index for Estimating Songbird Productivity: Case Study of the Golden-Cheeked Warbler
It is critically important to determine and understand relationships between endangered species populations and landscape and habitat features to effectively manage and conserve populations and the habitats they rely on. Several recent studies focused on the golden-cheeked warbler (Setophaga chrysoparia), an endangered songbird that breeds exclusively in central Texas, USA, have used a reproductive index to link pairing and breeding success to various factors of interest. However, no field test has evaluated the performance of a reproductive index at estimating productivity of golden-cheeked warblers or similar forest songbirds. We computed reproductive index ranks for 5 observers from multiple plots during 2013 and 2014 and compared these ranks with actual reproductive success determined from territory mapping and nest monitoring of color-banded adults. At the territory level, we found no significant correlation between 84 matched territories delineated by the reproductive index and territories delineated by intensive monitoring. At the plot level, index monitoring underestimated the total number of territorial males, but density from index monitoring was weakly correlated with actual density. We found no significant relationship for pairing success estimated from the reproductive index and actual pairing success, or with breeding success from the reproductive index with nest survival or actual breeding success, when controlling for observer. The reproductive index did not produce reliable estimates of reproductive performance at either the territory or plot level and we recommend intensive monitoring of color-banded individuals when absolute estimates of reproductive success rates or other demographic measures are required, such as in species viability or threat assessments.
Journal Article
Birds
Explores the remarkable structures and systems that make up the anatomy of a variety of different birds.
Book
Coevolution of coloration and colour vision?
The evolutionary relationship between signals and animal senses has broad significance, with potential consequences for speciation, and for the efficacy and honesty of biological communication. Here we outline current understanding of the diversity of colour vision in two contrasting groups: the phylogenetically conservative birds, and the more variable butterflies. Evidence for coevolution of colour signals and vision exists in both groups, but is limited to observations of phenotypic differences between visual systems, which might be correlated with coloration. Here, to illustrate how one might interpret the evolutionary significance of such differences, we used colour vision modelling based on an avian eye to evaluate the effects of variation in three key characters: photoreceptor spectral sensitivity, oil droplet pigmentation and the proportions of different photoreceptor types. The models predict that physiologically realistic changes in any one character will have little effect, but complementary shifts in all three can substantially affect discriminability of three types of natural spectra. These observations about the adaptive landscape of colour vision may help to explain the general conservatism of photoreceptor spectral sensitivities in birds. This approach can be extended to other types of eye and spectra to inform future work on coevolution of coloration and colour vision.
This article is part of the themed issue ‘Animal coloration: production, perception, function and application’.
Journal Article
The lion and the little red bird
A little bird discovers why the lion's tail changes color each day.
Book
Selective sweeps on different pigmentation genes mediate convergent evolution of island melanism in two incipient bird species
Insular organisms often evolve predictable phenotypes, like flightlessness, extreme body sizes, or increased melanin deposition. The evolutionary forces and molecular targets mediating these patterns remain mostly unknown. Here we study the Chestnut-bellied Monarch ( Monarcha castaneiventris ) from the Solomon Islands, a complex of closely related subspecies in the early stages of speciation. On the large island of Makira M . c . megarhynchus has a chestnut belly, whereas on the small satellite islands of Ugi, and Santa Ana and Santa Catalina (SA/SC) M . c . ugiensis is entirely iridescent blue-black (i.e., melanic). Melanism has likely evolved twice, as the Ugi and SA/SC populations were established independently. To investigate the genetic basis of melanism on each island we generated whole genome sequence data from all three populations. Non-synonymous mutations at the MC1R pigmentation gene are associated with melanism on SA/SC, while ASIP , an antagonistic ligand of MC1R , is associated with melanism on Ugi. Both genes show evidence of selective sweeps in traditional summary statistics and statistics derived from the ancestral recombination graph (ARG). Using the ARG in combination with machine learning, we inferred selection strength, timing of onset and allele frequency trajectories. MC1R shows evidence of a recent, strong, soft selective sweep. The region including ASIP shows more complex signatures; however, we find evidence for sweeps in mutations near ASIP , which are comparatively older than those on MC1R and have been under relatively strong selection. Overall, our study shows convergent melanism results from selective sweeps at independent molecular targets, evolving in taxa where coloration likely mediates reproductive isolation with the neighboring chestnut-bellied subspecies.
Journal Article
Extra-pair paternity drives plumage colour elaboration in male passerines
The elaborate ornamental plumage displayed by birds has largely been attributed to sexual selection, whereby the greater success of ornamented males in attaining mates drives a rapid elaboration of those ornaments. Indeed, plumage elaboration tends to be greatest in species with a high variance in reproductive success such as polygynous mating systems. Even among socially monogamous species, many males are extremely colourful. In their now-classic study, Møller and Birkhead (1994) suggested that increased variance in reproductive success afforded by extra-pair paternity should intensify sexual selection pressure and thus an elaboration of male plumage and sexual dichromatism, but the relatively few measures of extra-pair paternity at the time prevented a rigorous test of this hypothesis. In the nearly three decades since that paper’s publication, hundreds of studies have been published on rates of extra-pair paternity and more objective measures of plumage colouration have been developed, allowing for a large-scale comparative test of Møller and Birkhead’s (1994) hypothesis. Using an analysis of 186 socially monogamous passerine species with estimates of extra-pair paternity, our phylogenetically controlled analysis confirms Møller and Birkhead’s (1994) early work, demonstrating that rates of extra-pair paternity are positively associated with male, but not female, colouration and with the extent of sexual dichromatism. Plumage evolution is complex and multifaceted, driven by phylogenetic, ecological, and social factors, but our analysis confirms a key role of extra-pair mate choice in driving the evolution of ornamental traits.
Journal Article